Lock



unauthorized persons.

Patented ug`. 20, 1929.

UNITED STATES .PATENT oFF EDWARD P. BAIRD, OF EVANSTON, ILLINOIS, ASSIGNOB '.lO BAIE-.D LOCK C0., OF

1,725,557 ICE.

CHICAGO, ILIINOIS, A CORPORATION OF ILLINOIS.

LOCK.

`Application filed August 31, 1923. Serial No. 660,308. v

This invention relates to improvements in locks, and its purpose is to providea device comprising improved means for preventing the operation of the locking mechanism by One object of the invention is to provide a lock of the tumbler type comprising improved tumblers adapted to prevent the alignment thereof without the use of a properly'designed key. A further `object is. to provide a lock comprising tumblers of irregular shapes and dimensions designed to increase the difficulty of aligning them without the use of "a key. Other objects relateto various features of construc- .tion and arrangement such as will appear more clearly hereinafter.

The nature of the invention will be understood from the following specification taken with the accompanying drawings in which one embodiment is illustrated. In the drawings,

Fig. 1 shows a longitudinal vertical section through a lock of the cylinder type embodying features of the present invention;

Fig. 2 shows a. transverse section on the line 2-2 of Fig.'1 looking in the direction of the arrows;

Fig. 3 shows a. longitudinal horizontal section taken on the line 3-'3 of Fig. 1 looking in the direction of the arrows;

rel 10 is* adapted to be engaged by the mov able lock cylinder 14 which, in the embodiment illustrated, comprises two complemencross section having their Hat sides in contact Vtary parts 15-of substantially semi-cylindrical to form a. complete cylinder. These complev menta-ry members 15 are secured in assembled relation at their forward ends by means of a cap or collar 16 havin rotatable engagement with the bore 13 o the barrel and coactlng at its inner end with the annular flange 12. The cap 16 is provided with an annular flange '17 which engages the annular recess at the forward end of the -cvlinder 14 and the Fig. 4 shows a section taken on the line` lateral projections all of different lengths;vv

and Y Fig. 8 shows an elevation of one of the straight side lock tumblers employed in the inner end of the lock.

As illustrated in the drawings, the invention comprises a. barrel 10 which is substantially cylindrical in shape and adapted to be rigidly secured in thedoor or other device to be locked by any means suitable for the purpose. This barrel is provided with a cylindrical bore 11 terminating at its forward end -at the shoulder 12 which is formed at the inner end of the enlarged bore 13. The barcylinder is provided with an annular groove 18 into which the metal at the inner end of the cap 1s swaged, so that the parts 15 of the cylinder are securely held by the cap. At their inner ends, the complementary members 15 of the lock cylinder are secured to a substantiallycircular plate 21 by means of lugs 22 formed integrally with the members 15 and engaged holes 23 in the plate, the ends of the lugs being riveted to hold the parts securely in assembled relation. A pin 25 is mounted eccentrically on the plate-21and is adapted to operate the locking bolt, or the like, when the cylinder isturned in the barrel.

The plate 21 also has an arcuate notch 27 l formed ,in the outer edge thereof to receive a radial projection 28 which extends inwardly from the inner end of the bore 11 of the barrel 10. The projection 28 is adapted to engage the shoulder at the ends of the notch 27 to limit the angular movement in either direction of the cylinder 14.

The complementary members 15 of the lock cylinder have grooves 29 formed therein on their flat sides to form, when the parts of the cylinder are assembled, a series of tumbler slots 30 of rectangular cross section extending transversely through the lock cylinder.v The members 15 are further provided on their contacting sides with oppositely disposed grooves 31- and 32 forming together a vkey slot 33 adapted to receive a key 34. This key has shoulders 34* adapted to engage the end of the cylinder when the key is fully inserted, as shown in Fig. 1, and theblade 34" of the key is provided on one side with a rib 35 and on the kother side with a groove 36, adapted to engage a groove 37 and the projecting V- shaped rib 38, respectively, which are formed on the lateral walls of the key slot 33, as shown particularly in Fig. 6. The tumbler slots 30 engage all of these projections from the'corare occupied by a plurality of tumblers 40, two tumblers being located in each slot 30 in the embodiment illustrated. These tumblers are provided with rectangular apertures 41 adapted to be engaged by the blade 34b of the key and the key is provided along its edges with projections 42 which are adapted to coact with the walls of the slot 41, in the manner illustrated in Fig. 1, to align the curved edges 43 of the tumblers with the outer cylindrical surface of the cylinder 14, thus withdrawing the tumblers from the longitudinalI grooves 44 which are formed in the barrel 10 and permitting the cylinder to be rotated' in the barrel to operate the locking bolt through the movement of the pin 25.

To increase the difficulty of operating the lock cylinder without the use of a properly designed key, tumblers 40 are employed having outer edges of various different contours. In the innermost key slot 30 the tumblers preferably have the form illustrated in Fig.

8 Where the tumbler 4()a is shown as having parallel lateral edges 45 extending between the curved end surfaces 43. These straight side tumblers are 'adapted to fit closely thev lateral walls 44:l of the grooves 44 inthe barrel so that when thesev tumblers are in engagement with these grooves the vibration of the lock cylinder about its axis of rotation is prevented, thus making it impossible to eiect the alignment of the other tumblers by vibratory movements of the cylinder. Since the straight side tumblers 40*V are located in the innermost tumbler slot, they are the most difficult to reach -by persons seeking to pick the lock and therefore cannot be easily aligned.

The tumblers occupying the remaining tumbler slots 3() are of the general form illustrated in Figs. 7, 7 a, 7b and 7 c. The lateral sides 47rf are spaced apart distances less than the width of the tumbler slotsand they are provided at their corners with projections 48, 49, 5() and 51, all ofywhich differ in length measured from the longitudinal axis of the key slots 41 formed inthe tumblers. The ends of the projections are adapted to co-act with the walls of the tumbler slots and with the shoulders 44a of the grooves formed in the barrel. The different lengths of these projections serve normally to maintain the tumblers'out of alignment with each other and increase the diiiiculty of aligning them due to the engagement of the projections with the edges 52 of the side walls of the tumbler slots. If the tumbler slots are slightly out of alignment with the grooves 44 in the barrel., the projections onthe corners of the tumblers hook over the edges 52 of the tumbler slot walls and prevent the alignment of the tumblers in the tumbler slots except by the-use of a proper key. The dii'erent lengths of' these projections render it impossible to disners of the slot walls at one time, thus further insuring against the picking of the lock by unauthorized persons.

The key 34 is adapted to tit closely the key slot 33 formed in the cylinder 14, both later-4 release all .of the remaining tumblers from the grooves 44 in the barrel.

Although I have shown and described a. single embodiment of the invention for purposes of illustration, it will be understood that it maybe constructed in various other forms without departing from the scope of the appended claims.

I claim: 1 j

1. The combination in a lock, of a barrel, a

cylinder mounted in said barrel and having a plurality of tumbler slots, and a plurality of tumblers mounted in said slots, some of said tumblers having projections on their lateral sides, each projection on each tumbler being of different length than the other projections on that tumbler rendering the same laterally tiltable in the slots, the remainder of said Itumblers having straight sides snugly fitting the slots. L

2. The combination in a lock, of a barrel, a cylinder mounted in said barrel and having a plurality of tumbler slots,.and a plurality of tumblers mounted in said slots, some .of Vsaid tumblers having projections on their lateral sides, each projection on each tumbler being of a length diiferent than the other projecq tumblers having projections on their lateral sides, each projection on each tumbler being of 'a length different than the other projections on that tumbler, a clearance'between the adjacent wall of the slot and the edge of each of said tumblers for permitting the latter to be moved laterally, vthe remainder of said tumblers having straight sides snugly iitting the slots, said barrel having grooves Aadapted to be engagedby said tumblers, said grooves being adapted to be closely fitted by said tumblers having said straight sides.

4. The combination in a lock, of a barrel, a

cylinder mounted in said barrel and having a plurality of tumbler slots therethrough, and a plurality of tumblers mounted in said slots,

said barrel having longitudinal grooves adapted to be engaged by said tumblers, some of said tumblers being adapted to fit closely the lateral walls of said grooves, the remainder of said tumblers'having projections on their lateral sides, each of said projections on each tumbler being of a length different from the ot-her projections on that tumbler to render said tumblers tiltable to engage the edges of the Walls of said slots when improperly aligned in said cylinder.

5. The combination in a lock, of a barrel, a cylinder mounted in said barrel and having a longitudinal key 'slot therein, said cylinder having a plurality of transverse tumbler slots intersecting said key slot, a plurality of tumblers mounted in said tumbler slots and adapted to be aligned by a key'inserted in said key slot, said tumblers being tiltable laterally relative to the slots, said barrel having grooves adapted to be engaged by said tumblers, and projections formed on the outer edges of said tumblers to hook over the edges of the tumbler slots When the tumblers are not aligned, said projections on each tumbler being of a length different than the other projec'tions on that tumbler.

6. AThe combination in a lock, of a. barrel, a

cylinder mounted-- in said barrel and having a plurality of tumbler slots, and a plurality of tumblers mounted in said slots, some of said tumblers having projections. on their lateral sides, each said projection on'all said lattermentioned tumblers being of a different' tumblers having projections on their lateral v sides, the correspondingly positioned projections on adjacent tumblers being of different lengths. I ,l

8. The combination in aflock, of a barrel, a cylinder mounted in said barrel and having a plurality of tumbler slots, and a. plurality of tumblers mounted in said slots, some of `said tumblers having projections on their lateral sides, the correspondingly positioned projections on adjacent tumblers being of different lengths, the remainder of said tumblers having straight sides snugly fitting said slots. y EDWARD P. BAIRD. 

